Stabilizing mechanism for aeroplanes



May 16, 1933. w. c. JENKINS 1,909,632

STABILIZING' MECHANISM FOR AEROPLANES 2 Sheets-Sheet 1 Filed May 26. 1951 INVENTOR I VV/LL/AM C JENK/Ns in direct proportion to the amount of said WILLIAM c. JENKINS,

Patented May 16', 1933 I UNITED s'ira'ras PATENT OFFICE d1. DONGAN HILLS, NEW YORK, ASSIGIl'OR OF ONE-HA.LF TO FRITZ ZIEG-LER, 33., OF NEW YORK, N. Y.

STABILIZING MECHANISM FOR AEBOPLANES App'lication flled m 26, 1931. Serial No. 540,121.

I proposed, heretofore, to rely solely upon a counterbalan 'ng weight suspended from the fuselage .and connected to the control'lever,

or so-called-stick,so as to automatically control the latter and thereby maintain the aero-;

plane in longitudinal and lateral stability. For example, when a craft starts to bank about its longitudinal ancing weight is intended to maintain the control lever in a vertical position and thereby, through the usual connections to the ailerons, operate the latter to effect lateral stabilization. However, one of the factors which has not been given due consideration with. such a construction as thatsugnecessary to restorethe aeroplane to a stable utilization of. wind pressure against gested is'the centrifugal force created when the aeroplaneenters a'bank. This force is such that, in the absence of any counteracting influence upon the weight, it will overcome the gravitational effect thereof and swing the same outwardly with the result that the control lever will remain in practically the same relative position to the longitudinal axis of the craft as when the latter is in stable condition and the lever is neutral, and therefore the required adjustment of the ailerons condition will not take lace.

In order that this di culty may be overcome, the present invention contemplates the a device in the nature of a rudder which will resist the tendency of the centrifugal force to swing the same, and its connected control lever, in the direction of turning movement of the fuselage about its longitudinal axis as the aeroplane starts to bank, s'aidiresistance being axis, the counterbal turning movement. In this manner a force is created which counteracts the centrifugal force and through this medium the control lever is maintained in such position as to produce an adjustment of the ailerons which will effectstabilization of the aeroplane and prevent the same from'going into a steep bank. V

The inventive idea involved is capable of receiving a variety of mechanical expressions, one of which, for purposes of illustration, is shown in the accompanying drawin s wherein v f ig. I'is a sideelevation of an aeroplane equipped with the improved stabilizing mechanism, the elements of which are shown in operative position.

Fig. 2 is a diagrammatic front elevation of the aeroplane showing the same in a stable condition. p I

Fig. 3 is a similar view showing the aeroplane in a bank, with the stabilizing mech-. anism in the position it is adapted to assume in order to retutn the craft to a stable condition. Fig. 4 is an enlarged fragmentary longitudinal section through. the fuselage of the aeroplane illustrating in detailed elevation the elements of the stabilizing mechanism.

Fig. 5 is a sectional view of the mounting for the rudder device forming a part of the stabilizing mechanism, and 1 Fig. 6 is va fragmentary section of the control lever showing the mannerof connecting the rudder device thereto.

Although the stabilizing mechanism has been illustrated inconnection with abi-plane,

it will be readily understood that the same may be applied to other types-of aeroplanes without departing from the spirit or scope o the invention as expressed in the appended claims.

The fuselage 10 is of the usual construction having the wing 11 extending on opposite sides thereof and provided with ailerons 12 employed forlateral stabilization. It is desired to have it understood that where reference is hereinafter made to ailerons, this term is intended to include any type of stabilizing device. Mounted upon a r ock shaft 13 in the fuselage and having pivotal movements relative thereto is the customary control lever 14 connected in the usual manner by elements 15 to the ailerons 12, and by the link 16 and lever 17 to the elevator 18 at the tail of the craft.

The stabilizing mechanism comprising the essential features of the present invention and which is utilized to automatically control the lever 14 includes a universal connection mounted in the bottom of the fuselage 10. Said connection consists of ball and socket elements 19 and 20,-the latter of which is supported in a bearing 21. The element 19 is divided into sections each of which is carried by a portion of the bifurcated extremity of an arm 22 having a set screw 23 extending therethrough which is adjustable to expand and contract the sections of said element to operatively connect said arm to and disconnect it from the element 20. The upper end of the arm- 22 is adapted for connection to the lever 14 when it is desired to automatically control the latter and for this purpose carries a pivoted link 24 the free'end of which fits into a slot 25 and is'pr'ovided with pins 26 engageable on opposite sides of said lever, said link and its pins holding the lever relative to lateral, fore and aft movements thereof.

Depending from the universal connection is a rudder post 27 having a turning movement about its own axis relative to the element 20 through the medium of the opposed pins 28 and slots 29. A weighted rudder 30 is carried by the lower end of the post 27 and said elements are adapted, by reason of said universal connection to be swung upwardly to a substantially horizontal and inoperative position, as shown in dotted lines in Fig. 4. For this purpose a flexible element 31 is connected to the rudder 30 and passed over a pulley 32 to a drum 33 adjacent th aviators seat so that he may readily adjust said rudder to the desired position.

The turning movement of the post 27, and consequently of the rudder 30, which occurs when the fuselage of the aeroplane starts to.

turn or tilt about its'longitudinal axis, is under the control of a tiller 34 one end of which is adjustably connected to the post 27 and its other end slidably and pivotally supported in a yoke 35 depending from the fuselage 10. The adjustable connection of the tiller to the rudder post which is effected through the series of openings 36 in the latter, is provided to vary the amount of turning movement of 7 said post for any given pivotal movement of said tiller.

In practice, after the aviator has attained the desired elevation and headed the aeroplane in the selected direction of travel, should he wish to place the lever 14 under the automatic control of the stabilization mechanism, the rudder 30 is first lowered into its operative position by unwinding the element 31 from th drum 33. The lever 14 is then adjusted, if necessary, to a fore or aft position to compensate for any tail or nose heaviness of the craft so as to secure longitudinal stability thereof. Thereafter, the arm 22, which is at this time free to move relative to the element 20 of the universal connection because of the contracted position of the element 19, is latched to the lever 14 through the medium of the link 24, whereupon the set screw 23 is manipulated to expand the element 19 against the element 20 and thereby, in eflect, form a rigid connection between the lever 14 and the rudder 30.

Now, should the aeroplane havea tendency to nose downwardly into a dive or upwardly into a stall, the Weighted rudder 30 and its post 27 will remain in vertical position as the fuselage turns about a transverse axis. This relative movement of the fuselage to the rudder during which the lever 14 is held stationary has the effect of exerting a push or pull upon the lever 17 through-the connection 16, thereby adjusting the elevator 18 to bring the fuselage back to a stable position.

As will be understood from the foregoing description, should the fuselage of the aeroplane start to tilt about the longitudinal axis thereof, sole reliance is no longer placed upon the weight of the rudder to maintain the lever in position to cause the operation of the ailerons 12. This is due to the fact that the rudder cannot be practically made sufficiently heavy .to overcome the centrifugal force created when the aeroplane is banking, as it Will do after tilting unless measures are taken to stabilize the same, with the result that said force will overcome the gravitational effect of the weight of the rudder and swing the same outwardly so that it will remain in substantially the same relative position to the fuselage as when the latter is in stable condition, as indicated by the single dotted line in Fig. 3. Therefore, with the lever 14 locked to the rudder, it would swing therewith and the ailerons would remain in their neutral positions.

The above difliculty is overcome in the present construction by the turning movement which is imparted to the rudder about its post 27 as an axis so as to present a surface of the rudder to the air pressure and thereby create a counteracting force to that which has a tendency to swing the rudder outwardly. Such counteracting force will immediately cause the fuselage to restore to its normal stable position and therefore prevent the same from tilting so far as to send the aeroplane into a bank'which would result in a turning movement relative to the direction of flight. By reference to Fig. 3, it will be seen that as the aeroplane starts to tilt, the yoke 35 swings away from its vertical plane and in so doing produces a pivotal movement of the tiller 34 which, being rigidly the case of a very sudden and strong gust of wind, the aeroplane may be thrown into banking position. The rudder would then swing outwardly a slight distance as indicated in dotted lines in Fig. '3 but it will nevertheless be turned as described and the force necessary to prevent a complete outward swinging movement will be produced. Therefore, the lever 14 will be maintained in a position which will, owing to the greater inclination of the wings of the aeroplane, effect the desired adjustment of the ailerons to restore the machine to a laterally stable condition. When the aeroplane is inadvertently throwri .into a bank and, as a consequence is made to turn from original direction of flight, it will, due to its banked position, be prevented from side slipping or skidding. Then, as the machine is being brought to its stabilized position, by the action of the rudder 30, and, while it is still describing a turning movement, any side slipping which might result in an accident is prevented by the pressure of the Wind against the side of the fuselage and. tail of the machine which are on the outer s1de of the arc traversed during said turnlng movement. Said pressure immediately acts to straighten the lineof flight and' has the same effect as when an aviator, in making a landing, throws the tail of his aeroplane to one side or another when it is desired to reduce the speed of the machine.

When preparing to land, the lever 14 is disconnected from the arm 22 and the rudder raised to its inoperative position by winding-the element 31 upon its drum 33.

What is claimed is 1. In an aeroplane, the combination with ailerons, and a control lever therefor; of

means connected to said lever and actuated, by a movement of the fuselage of the aeroplane about its longitudinal axis, to utilize the air pressure against said means to maintain said] lever in a position wherein the ailerons willbe effective to restore said fuselageto a stable condition.

2. In an aeroplane, the combination with ailerons, and a control lever therefor; of a rudder device depending from "the fuselage of the aeroplane and connected to said ,lever and actuated, by a tilting of the aeroplane aboutits longitudinal axis, to turn said device so that a surface thereof is affected by air pressure to malntaln sa1d lever in a position to restore said aeroplane to a stablecondition. a

3. In an aeroplane, the combination with ailerons, anda control lever therefor; of a rudder device having a universal connection with the fuselage of the aeroplane andcon ndcted to said control lever, and means effective when the aeroplane tilts about its longitudinal axis to turn said rudder device in a direction in which air pressure thereagainst will maintainsaid lever in av position to cause operation of said ailerons.

4. In an aeroplane, the combination with ailerons, and a control-lever therefor; of a rudder mounted for swinging and turning movements relative to the fuselage of the aeroplane and connected to said lever, and

means effective when the aeroplane tilts about its longitudinal axis to turn said rudder in a direction in which air pressure thereagainst will maintain said lever in a positionto cause operation of said ailerons.

5. In an aeroplane, the combination with ailerons, and a control lever therefor; of a rudder device depending from the fuselage of the aeroplane and connected to said lever and actuated, bythe aeroplanetilting'about its longitudinal axis, to turn said device so that a surface thereof is afi'ected by air pressure to maintain said lever in a positionto restore said aeroplane to. a stable condition, the amount ofturning movement of said device being-in direct proportion to the degree of inclination of the aeroplane while it is in tilted position. a

6. In an aeroplane, the combination with ailerons, and a control lever therefor; of a rudder mounted for swinging and turning movements relative to the fuselage of the aeroplane and connected to said lever, and a tiller connected to said rudder and fuselage and operable when the latter moves about its longitudinal axis to turn said rudder in a y direction in which air pressure thereagainst acts to' maintain said lever in position to effect operation of sa1d ailerons.

7. In an aeroplane, the combination with said ailerons. v v

8. In an aeroplane, the combination with ailerons, and a control lever therefor; of a rudder deviceconnected to said lever and turnable relative thereto, andmeans responsive to a banking movement of the aeroplane for turning said rudder device in a direction away from the inner arc traversed by the aeroplane. during its banking movement.

120 said lever in a; position to effect operation of 9. In an aeroplane, the combination with ailerons, and a control lever therefor, of a rudder device suspended from the fuselage of the aeroplane for swinging and turning movements relative thereto, means to connect said device to said control lever, and a tiller connected to said device and responsive to a banking movement of the aeroplane for turning saiddevice in a direction away from the inner arc traversed'by the aeroplane during said movement thereof.

10. In an aeroplane, the combinationawith ailerons, and a control lever therefor, of a rudder device suspended from the fuselage of the aeroplane for swinging and. turning movements relative thereto, means to connect said device to said control lever, and a tiller connected to said device and responsive to a banking movement of the aeroplane for turning said device in a direction away from the inner arc traversed by the aeroplane during said movement thereof, and a support for said tiller relative to which the same has pivotal and linear movements.

11. In an aeroplane, the combination with ailerons, and a control lever therefor, of a rudder device suspended from the fuselage of the aeroplane for swinging and turning movements relative thereto, means to connect said device to said control lever, and a tiller connected to said device and responsive to a banking movement of the aeroplane for turning said device in a direction away from the inner arc traversed by the aeroplane during said movement thereof," and a support for said tiller relative to which the same has pivotal and linear movements, the means to alter the position of said tiller relative to its connection to said device and said support.

12. In an aeroplane, the combination with ailerons, and a control lever therefor; of a universal connection one of the elements of which is adjustable relative to the other, an arm extending from the first named element, means to detachably connect said arm to said control lever, a rudder supported by said universal connection and having a turning movement relative thereto, and means to turn said rudder when the aeroplane enters a bank.

13. In an aeroplane, the combinationwith ailerons, and a control lever therefor; of a weighted rudder device supported by the fuselage of the aeroplanefor swinging and turning movements relative thereto, means to connect said device to said control lever, and means to turn said rudder when the aeroplane enters a bank.

14. In an aeroplane, the combination with ailerons, and a control lever therefor; of a weighted rudder device supported by the fuselage of the aeroplane for swinging and turning movements relative thereto, means aeoaeea movement being dependent upon the degree of inclination of the aeroplane while in its banking position.

15. In an aeroplane, the combination with ailerons, and a control lever therefor; of a universal connection, means to joint the same to said control lever, a weighted rudder depending fromand having a turning movement relative to said connection, a support, and a tiller connected to said rudder and having sliding and pivotal movements in said support, said movements being efi'ected respectively, by turning movements of the fuselage of the aeroplane about transverse and longitudinal axis.

In testimony whereof, I have affixed my signature.

WILLIAM C. JENKINS.

to connect said device to said control lever,

and means to turn said rudder when the aeroplane enters a bank, the amount of turning 

